KVM: nVMX: Drop testcases that are redundant with the primary VMX testcase

The overarching VMX test binary, i.e. vmx.flat, contains a large number
of individual tests.  In addition to a kitchen sink testcase, "vmx",
many (but not all) of the individual tests also define their own test
case.  Drop all such individual test cases that can use the generic
umbrella testcase, e.g. don't need SMP, 2gb ram, etc..., so that running
all unit tests doesn't double up on said tests.

Alternatively, "vmx" could be removed, but doing so would provide little
value (the tests are relatively fast and stable), be a maintenance
nightmare, and run the risk of unintentionally omitting tests from the
config.

Ideally, the config would find a middle ground and group the vmx tests
into a handful of meaningful testcases, but the tests exposed by
vmx.flat currently don't play nice with that approach.  In other words,
the tests themselves need to be reorganized before the config can follow
suit.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>